private void btnParseQuery_Click(object sender, EventArgs e)
{
string inputString = txtSqlQuery.Text;
var input = new ANTLRStringStream(inputString);
var lexer = new EntityLexer(input);
var tokens = new CommonTokenStream(lexer);
var parser = new EntityParser(tokens);
var result = parser.prog();
var tree = result.Tree;
txtParseStringTree.Text = tree.ToStringTree();
var treeNodeDrawable = new ASTreeNode(tree);
if (pictureBox1.Image != null)
{
pictureBox1.Image.Dispose();
pictureBox1.Image = null;
}
Image image = new VisualAST(treeNodeDrawable).Draw();
pictureBox1.Image = image;
}